Air conditioning conduit fitting



Oct. 3, 1944. R. E. PECK AIR CONDITIONING CONDUIT FITTING Filed July 6, 1942' avg/(a g,

Patented Oct. 3, 1944 AIR CONDITIONING CONDUIT FITTING Robert E. Peck, Cincinnati, Ohio, assignor of onefourth to Wm. Burchenal and one-fourth to Morss Lippincott, both of Cincinnati, Ohio Continuation of application Serial No. 308,591, This application July 6, 1942, Serial No. 449,882

December 11, 1939.

Claims.

This invention relates to the art ofconstructing and installing ducts and conduits of the type employed in air conditioning and heating systems. The invention .is directed particularly to the fabrication or the manufacture of elbows and angle fittings which are required for leading conduits through turns and bends as when the conduit is to be taken around a corner or is to be taken upwardly from a horizontal run. The elbows or fittings required for such purposes may be of an angle less than 180, for instance, 30, 45, 90 or 120, to suit the requirements of the installation in the building.

The'elbows and fittings of the present invention are adapted especially to be used in conjunction with conduit of the type shown in Robert E. Peck Patent No. 2,226,523 of December 24, 1940, which consists essentially of tubular lengths of asbestos containing material or laminated asbestos paper adapted to be joined to one another to form straight run sections. Accordin to the Peck patent the sectional lengths of duct-work are comprised of one, tube which is rigid and strong and another tube which contains air cavities; these tubes are telescopically or slidabl as sociated one within another and they are assembled into a straight run of conduit on the job by staggering the sections with respect to one another, so that they may telescopically be joined together. In this manner the joints between the outer tubes occur intermediate the joints between the inner tubes. The; unitary lengths each comprising an inner and an outer tube are adapted to be furnished to the job for assembly and installation there, and one of the primary objectives of the present invention has been to provide elbow fittings which also may be fabricated in a simple manner on the job from unitary lengths, or parts of them.

In the past sheet metal elbows and fittings, as well as sheet metal conduit itself, have been fabricated in the shop, then taken to the job for installation. But before this can be done a skilled person must visit the building in which the ductwork is to be installed, make the necessary measurements, prepare drawings or sketches, and then turn these over to the tinsmith or'sheet metal worker for him to reproduce in metal. The process is laborious and expensive, and the present invention contemplates elbow fittings which may be made at the point of installation and with but a hammer and a saw for tools, Whether from unitary lengths of duct of the type shown in the aforesaid Peck patent orfrom other sui ab fi 1311- 'bular material preferably of a fibrous nature that may be sawed. M

It is also the objective of the presentinven tion to provide elbow fittings and turns in which vanes are present for directing the flow of air and diverting it along a new path in such manner that the resistance to flow at the turn is minimized. Vanes of this type are sometimes called duct turns; they are of crescent shape and are of substantial thickness at the mid portion while the edges are somewhat feathered. The radii at the inner and outer Walls are so adjusted that the area diagonall of an elbow is substantially the same as that of the. run of duct. By this arrangement the Velocity of 'the air passing through the turn is substantially the same a the velocity of the air in a run of .duct

preceding the turn, and the curved faces of the vanes direct the flow and minimize the turbulence which would otherwise occur. It has been an objective of the present invention to provide a fitting in which such vanes may be arranged accurately as to position andalso firmly held in place. p

The invention, briefly, is predicated upon the concept of providing'mitred elbow-formin-g'sections adapted to be joined toone another to provide the necessary turn or elbow and locating vanes along the mitre line. The invention further is predicated, however upon the corrcept of utilizing the vanes themselves as the means for connecting the mitred sections one to the other. This result preferably is obtained by cutting a single length of, duct diagonally into two pieces, the one piece, when placed in reverse complementary position with respect to the other, joining the mitred face of the other piece to provide the desired elbow formation. The vanes or duct turns of the elbow stracldlethe mitre or joint line and fasteners project through the walls of the respective sections at opposite sides of the mitre line into the bodies of.the vanes at each end thereof so that the mitred sections are joined to one ,another through the vanes. Otherwise expressed, each of themitred sections is fastened to the vanes and they, therefore, serve the double purpose of directing'the flow of air through the fitting and of holding the elbow-forming elements of which the fitting is constituted in assembled relationship. The f asteners also hold the vanes firmly in position so that during usage they do not become loosened or tend to pivot on their axes to impair the air flow.

Since it is requisite that the vanes be installed relatively accurately in predetermined positions in the elbow to assist the flow of air, it is desirable that there be guide means designating the points at which nails or cleats are to be driven through the walls of the elbow-forming membersin-order that the nailswill strike square.- 1y into thebody portion of the vane-to form a rigid joint. Inasmuch as the ends of the vanes are overlapped by the elbow-forming members; the ends of the vanes are thus concealed andthe guide means tells the fabricator where the nails are to be driven. Forthis purposetwoimplements are provided; oneis a nailing strip of metal or paper carrying punched holesor printed marks in predetermined positions for indicating. the nailing positions, and the other is a template-- or fixture for positioning the vane while a nail is being driven into it through the Wall of one of the sections such that its curved surfaces properly direct the How ofairthrough the elbow.

In general, an elbow is made by-first cutting a-length of .conduit diagonally tov the given-angle required to form. thedesired elbowand, next, cuttingv up a lengthof vane or duct-turn into .piecesdimensionedto fitin between theopposite sidev walls-:of the mitered. piecesgoing to make up the. elbow. A nailing striphaving nailing guide marks on. it at. predetermined intervals (corresponding to. the. desired spacing of the vanes) is placed along. the mitred; edge. of one of the elbow-formingv pieces, preferably such that one half of. the nailing stripmmarginally overlaps. the mitred elbow-forming piece, while the other. half extends beyond themitred edge. A-vane is then located onithe fixture for posit tioning the vane as described abovea The fixture itself. isthenslidalong the mitred. edge until. it is-inalignment withone of the'predetermined positions indicated by the nailingstrip, and a nail or fastener isdriven through the nailingstrip at the markedspot-lntothe body of the vane. Successiveevaneaare fastened to this mitred duct turn member in the same manner and afterward the-other elbow-forming piece is-slipped into .position. with. itsmitred edge abutting the mitred. edge of the first; piece, and nails then shapes; but preferably is comprised of a. body which is-configured toreceive. andhold avane inagiven position relative. tothe template, a slide. piece carried by the body'ior engagement withthemitred edge. of an elbow-forming meme ber, andapointer or. other suitable indicating means positioned relative to. the. body so that,

when the-pointer issalignedwith the nail holes or. otherv appropriate marks or indi-cia; upon'the naili'ng strip, the, vane isin position to receive the nailor fastener.

Themitred, elbow-forming sections-ama'y be. of

the, double wall type as shown in the aforesaid Beck patent or. of the-single wall type utilizing,

.for example,j the stifi and rigidportion ofsuch a conduit from which to form an elbow. In such an instance the elbow maybe left uncovered or, if desirable, the other section of such a conduit may be out along the corresponding mitre line and the pieces then respectively slipped over the assembled elbow until their mitred edges meet. An advantage in the latter type of construction resides-in-thefact that. the-outer sections may project beyond the entrance-and exit faces of the elbow itself to provide a staggered joint at the point of connection between the elbow and thestraight runof duct-work preceding or succeedlng it.

Atypical-embodiment of the present invention is illustrated in the accompanying drawing wherein the'fabrication of a angle fitting is disclosed.

In the drawing;

Figure 1- is aqplan view of the disassembled sections of a 90.angle fitting.

Figure 2 is an end elevation of the upper sectionshown in Figurel.

Figure 3.is a plan. view of. thefittings shown in Figure 1 in assembled condition.

Figure 4.is a planview of the. fittingashown in Figure 3, after the exterior or outer section of conduit has been moved. intov positioncovering the inner. sections-attheangle. joint.

Figure 5 is aperspectiveview of a -tool. which I. employ in. connection with. the a positioning; oi the air deflecting blades,.as. shown in the assembly illustrated." a

Figurefi is. a perspective, view of anaindirecting vane or blade.

Figure '7 is a perspectiveview.ofamodified.type of, air directing vane.

As shown in the drawing, andlparticularly Fig,- ure. 1, eachfitting comprises: at leasttwoelements, l and.2, each havingaflface. 3'.- extending transversely of it along adiagonal. line, in this case a 45 angle, such that .the. sections I and 2 meet one another at a mitred IJ'oihttoformaBO" or right angle fitting.

The vanes which are to, be mountedlat the juncture of the mitred edges. 3. are. indicated; at

4 and preferably are made of compressed asbestos Thus, in Figure 7; a vaneis shown formed from a metal shell 5 filled in as at 6-, with-a mixture of cement and'fine cinders-whichhardensinto a rigid bodywhichwill receive andhold the shanks, or'nalls, or cleats tenaciously.

In the fittings shown which, fox-example; may have an interior dimension of 5%" by 2 /2 three air deflecting blades orvanes are utilized to direct theair through theturn without substantial loss in velocity. The vanes Il -have back walls Iwhich are slightly rounded at their junc ture and, for the partlcular fitting being described, they may have a dimension ofapproximately' 2 for: each-wall. A curved'front wall 8 constitutes the airdeflecting-face.

It is' desirable that-each vane tbe positloned such that," the. curve 'of the: frontwall 8* is= sub stantially tangential to the path of'the air stream entering and emergingtfrom the-turn; The three vanes kin the embodiment: disclosed are spaced approximately. equidistantly. from one another: V

In accordance with the present invention, and as shown particularly in Figure 3, each end of each van'e preferably receives fasteners 9 and I0, respectively, the fasteners 9 passing through the wall of one elbow-forming section and longitudinally into the body of the vane at one side of the mitre line H, and the fasteners I passing through the wall of the other elbow-forming section at the other side of the joint line I I. Thus, each of the mitre sections is joined to the vanes such that they have the function of directing the flow of air and the structural purpose of holding the mitre sections to one another in assembly As previously described, and as readily may be seen from Figures 1 and 3, the ends of the vanes straddle the joint and are therefore concealed by the walls of the elbow-forming sections. While the workman might be able to drive the nails accurately into the vanes through one of the sections, he would encounter difiiculty;

when the other is put on because of the concealment. It is also important that the deflecting faces of the vanes be positioned to guide the flow of air without obstructing it. To facilitate the unskilled workman in obtaining this result a nailing strip or guide is utilized. This is designated I! in the drawings and is a guide strip of metal or paper having holes punched through it or nail marks printed on it as shown at I3. These marks are arranged in pairs, the mark of each pair being spaced apart from one another a distance such that nails or fasteners driven through each of the marks of the pair may strike squarely into the body of a vane appropriately arranged beneath the strip.

As shown in the drawings the guide strip [2 contains three sets of nailing marks, one pair for each vane, and also may be provided with a guide line I4 adapted to overlie and be aligned with the mitred edge such that the nailing marks l3 may be spaced equidistantly at opposite sides of the mitre line and from the diagonal guide line H which may be used for locating purposes as subsequently described.

The tool or fixture illustrated in Figure 5 has a straight edge portion I6 and a template ll of elliptical shape, the curvature of the faces thereof being substantially complementary to the curvature of a face 8 of an air deflecting vane. The template also preferably has end stops |8-l8 which serve to position a vane on the template and align the vane in predetermined position with respect to the straight edge. The template is fastened to the straight edge portion l6 such that the straight edge is aligned symmetrically with respect to the curved faces of the template. The template also has upon it edges I9, or suitable scratch lines so located with respect to the template that when it is aligned with a mark or guide line l5 of the nailing strip, the Vane held by the template is properly located beneath th nailing marks l3.

In assembling a fitting, a guide strip 12 is first positioned over the mitred edge of one of the elbow-forming sections with the median line 14 in alignment with the mitred edge of the section. The strip I2 is shifted along the edge until the nailing guides I3 are positioned at the points at which the vanes are to occur. Now, a vane, cut to length to fit across the face of the elbow-forming section between the inner faces of the walls thereof, is laid on a face of the fixture, the two are held together and the straight edge I6 is placed to lie against the mitre edge of the elbowforming section. The fixture is shifted along the edge until the vane lies appropriately beneath one of the nail guides with marker edge is aligned with the corresponding line 1'5 of the strip. A nail or fastener is then driven through the appropriate nailing mark l3 into the body of the vane, and succeeding vanes are installed in the same manner. This elbow section, with the vanes attached to it at their one end, then may be flopped over and the vanes fastened in similar manner at their other end.

Subsequently the other elbow-forming section is slipped over the portions of the vanes which project beyond the mitred edge of the first, and the two sections caused to abut one another at the joint line. Nails then are driven through the other set of nail guides l3. Since these are located in predetermined positions with respect to the nails previously driven they will strike squarely into the body of the vanes which are now concealed. Fasteners finally are driven into the vanes at the opposite face of the fitting in the same manner to complete the assembly of a single Wall fitting.

Having a fitting constructed in this manner, outer tubular elements, appropriately cut to fit together on the mitre line, may be slipped over the assembled elbow-forming sections respectively, as shown in Figure 4, when heat insulation is desired.

In the construction shown in Figure 4 it will be ob erved that the inner member 2 at one end of the fitting projects beyond the outer member 20 thereof, while the outer member 2| at the other end of the fitting projects beyond the inner member. This result readily is accomplished by taking a section of multi-tube conduit of the type shown in the Peck patent and cutting it diagonal- 1y so as to obtain two pieces of unequal length, and the tubes are disassembled. The one set of the tubes, e. g., the inner tubes are joined together to form a fitting in the manner just described but this fitting will have one long leg and one hort leg. Next a longer tube of the other (i. e. outer set) is slid over the inner section of shorter length and vice versa, so that the fitting thus is arranged for male and female connections at both its ends and staggered joints are provided at each of the points of connection of the fitting to straight run conduits.

The elbows or turns fabricated in accordance with the present invention may be dismantled at will in which case the vanes may be reutilized, and while one form of template which has been found suitable and convenient to the unskilled fabricator has been disclosed in the present application, other fixtures or locating devices may be utilized and, in fact, a careful workman after little experience has no great difiiculty in forming the elbows and nailing the vanes accurately without any appliance of this sort, using nails, screws, or U-shaped cleats which extend across the joint line if desired to hold the parts in rigid assembly.

This application is a continuation of my application Serial No. 308,591, filed December 11, 1939, which has now been abandoned in favor of this application. 7

Having described my invention, I claim:

1. An elbow fitting for a duct, comprising tubular members of asbestos material adjoining one another along a mitre line to constitute an elbow, a plurality of duct-turn elements extending across the tubular opening in the elbow so as to direct the fiow of air therethrough, the said duct turn elements having their ends respectively -;by :the "tubular imem'bers "are joined :to one -anzother .thrzough v.thce :duct turn elements and the :duct turn-:elements aref'heldjnpredetermined pou=sitioninntheielbow.

' 2. A- fibrous fitting for use inconduit construction comprisingi-two elements; eachhaving inner 1 0 :and outer: sectionsgandreach :having -an"end'.iefdge :extending diagonally ofzits '1ength,'said edges T fitted :together to; formra'desiredangle fitting, and :vanesisecuredmlong theimeeting edge of the invanes :secured along the :meeting edge of ithe inner sections, and *nails extending "through the .w-alls of the inner sections into '-the bodies of. said vanes. Y

conduit material into attachmentwith said vanes to form aself-sustainingassembly-of saidditting. :5. -An :elbow fitting, :whicncomprises :mitred mergsections to'direct air currents through the fit- 1 :5 :sectionsmfzduct-way:adjoiningone anotherzalong --ting;aand removable fasteners-"extending through :WEtIIS of sai'diinner sections and embedded in:said

vanes.

'"3; Afibrousffitting "for use in conduit construca..=mitred line 2 and vanes disposed within the sectionsncentrally :along :the mitred linenin spaced relationship, and Tfasteners extending through the .vvalls of athe respective mitredzsections into :tion'fcomprising two elementsyeachihaving inner 20 'the :bodies .of the z-van'es arespectively for interwan'dsiouter sections,::an'deach-having an end edge extending diagonally of its length, said iedges fitted together to form a desired-anglefitting,

connecting "theimitred sections to 'one "another,

and :foriholding the :vanesiin the elbow.

TROBERT PECK. 

